@root 为什么是Runtime Error？

#include<iostream>
using namespace std;
int main(){
    int a,b;
    char c;
    cin >> a >> b >> c;
    if (c == '+'){
        cout << a + b;
    }
    else if (c == '-'){
        cout << a - b;
    }
    else if (c == '*'){
        cout << a * b;
    }
    else if (c == '/'){
        cout << a / b;
    }
    else{
        cout << "Invalid operator!";
    }
    return 0;
}